[SPARK-54397][PYTHON] Make UserDefinedType hashable

### What changes were proposed in this pull request?
Fix the hashability of `UserDefinedType`

### Why are the changes needed?
UDT is not hashable, e.g.
```
In [11]: from pyspark.testing.objects import ExamplePointUDT

In [12]: e = ExamplePointUDT()

In [13]: {e: 0}
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[13], line 1
----> 1 {e: 0}

TypeError: unhashable type: 'ExamplePointUDT'

In [14]: from pyspark.ml.linalg import VectorUDT

In [15]: v = VectorUDT()

In [16]: {v: 1}
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
Cell In[16], line 1
----> 1 {v: 1}

TypeError: unhashable type: 'VectorUDT'

```

see https://docs.python.org/3/reference/datamodel.html#object.__hash__

> If a class does not define an __eq__() method it should not define a __hash__() operation either; if it defines __eq__() but not __hash__(), its instances will not be usable as items in hashable collections.

> A class that overrides __eq__() and does not define __hash__() will have its __hash__() implicitly set to None. When the __hash__() method of a class is None, instances of the class will raise an appropriate TypeError when a program attempts to retrieve their hash value, and will also be correctly identified as unhashable when checking isinstance(obj, collections.abc.Hashable).

### Does this PR introduce _any_ user-facing change?
yes, `hash(udt)` will work after this fix

### How was this patch tested?
added tests

### Was this patch authored or co-authored using generative AI tooling?
no

Closes apache#53113 from zhengruifeng/type_hashable.

Authored-by: Ruifeng Zheng <ruifengz@apache.org>
Signed-off-by: Dongjoon Hyun <dongjoon@apache.org>

Author: zhengruifeng

python/pyspark/ml/tests/test_linalg.py

@@ -364,6 +364,9 @@ def test_unwrap_udt(self):
         ]
         self.assertEqual(results, expected)
 
+    def test_hashable(self):
+        _ = hash(VectorUDT())
+
 
 class MatrixUDTTests(MLlibTestCase):
     dm1 = DenseMatrix(3, 2, [0, 1, 4, 5, 9, 10])
@@ -394,6 +397,9 @@ def test_infer_schema(self):
             else:
                 raise ValueError("Expected a matrix but got type %r" % type(m))
 
+    def test_hashable(self):
+        _ = hash(MatrixUDT())
+
 
 if __name__ == "__main__":
     from pyspark.ml.tests.test_linalg import *  # noqa: F401

python/pyspark/sql/tests/test_types.py

@@ -2076,6 +2076,44 @@ def test_repr(self):
         for instance in instances:
             self.assertEqual(eval(repr(instance)), instance)
 
+    def test_hashable(self):
+        for dt in [
+            NullType(),
+            StringType(),
+            StringType("UTF8_BINARY"),
+            StringType("UTF8_LCASE"),
+            StringType("UNICODE"),
+            StringType("UNICODE_CI"),
+            CharType(10),
+            VarcharType(10),
+            BinaryType(),
+            BooleanType(),
+            DateType(),
+            TimeType(),
+            TimestampType(),
+            TimestampNTZType(),
+            TimeType(),
+            DecimalType(),
+            DoubleType(),
+            FloatType(),
+            ByteType(),
+            IntegerType(),
+            LongType(),
+            ShortType(),
+            DayTimeIntervalType(),
+            YearMonthIntervalType(),
+            CalendarIntervalType(),
+            ArrayType(StringType()),
+            MapType(StringType(), IntegerType()),
+            StructField("f1", StringType(), True),
+            StructType([StructField("f1", StringType(), True)]),
+            VariantType(),
+            GeometryType(0),
+            GeographyType(4326),
+            ExamplePointUDT(),
+        ]:
+            _ = hash(dt)
+
     def test_daytime_interval_type_constructor(self):
         # SPARK-37277: Test constructors in day time interval.
         self.assertEqual(DayTimeIntervalType().simpleString(), "interval day to second")

python/pyspark/sql/types.py

@@ -2003,9 +2003,6 @@ def fromJson(cls, json: Dict[str, Any]) -> "UserDefinedType":
             UDT = getattr(m, pyClass)
         return UDT()
 
-    def __eq__(self, other: Any) -> bool:
-        return type(self) == type(other)
-
 
 class VariantVal:
     """